Electromagnetic properties of composite filaments with ferromagnetic fillers for 3D printing

The paper presents the results of a study of composite materials based on the polymer acrylonitrile styrene acrylate (ACA) and filler M-type hexaferrite (BaFe12O19). The results of X-ray diffractometry of hexaferrite powder are presented. The porosity of the obtained composite filament samples was studied. After 9 extrusion cycles, the porosity is reduced to less than 1%. In the EHF range, the transmission coefficient through a sample of a composite material was measured. A sharp decrease in the transmission coefficient is observed in the frequency range from 42 to 55 GHz, which is due to the natural ferromagnetic resonance in BaFe12O19 hexaferrite

Modeling of the Interaction of GRB Prompt Emission with the Circumburst Medium

We present methodology and results of numerical modeling of the interaction of GRB prompt emission with the circumburst medium using a modified version of the multi-group radiation hydrocode STELLA. The modification includes the nonstationary photoionization, the photoionization heating and the Compton heating along with the hydrodynamics and radiation transfer. The lightcurves and spectra of the outcoming gamma-ray, X-ray and optical emission are calculated for a set of models (shells) of the circumburst environment, which differ in dimensions, density, density profile, composition, temperature. In some cases total bolometric and optical luminosities can reach 10^47 and 10^43 erg/s respectively. These effects can be responsible for irregularities which are seen on lightcurves of some GRB's X-ray and optical afterglows.Comment: 27 pages, 16 colour figures, this version is translated by authors, so it differs from that, which is published in Astronomy Letter

Electromagnetic properties of composite filaments with ferromagnetic fillers for 3D printing

The paper presents the results of a study of composite materials based on the polymer acrylonitrile styrene acrylate (ACA) and filler M-type hexaferrite (BaFe12O19). The results of X-ray diffractometry of hexaferrite powder are presented. The porosity of the obtained composite filament samples was studied. After 9 extrusion cycles, the porosity is reduced to less than 1%. In the EHF range, the transmission coefficient through a sample of a composite material was measured. A sharp decrease in the transmission coefficient is observed in the frequency range from 42 to 55 GHz, which is due to the natural ferromagnetic resonance in BaFe12O19 hexaferrite